JUMP RELAXATION MODEL AND COUPLING MODEL - A COMPARISON

Frequency-dependent electrical conductivities of structurally disordered solid electrolytes are characterized by the well known Jonscher power-law behaviour which merges into plateaus at low and high frequencies. The jump relaxation model and the coupling model, introduced by the present author and by K.L. Ngai, respectively, have both been conceived in order to explain the experimental findings. The two models have an essential common feature: they both emphasize the slowing of the relaxation with time. On the other hand, the models are complementary to each other. While the coupling model has been constructed on the basis of very general physical principles, without the necessity of knowing the detailed microscopic dynamics in the electrolyte, such a microscopic view is provided by the jump relaxation model.